A spinning or twisting machine can have a plurality of stopping devices which are located at respective work stations of a set of drafting rolls or supply rolls. These stopping devices are each associated with a yarn break sensing device which can activate the stopping device.
A spinning machine making yarn from roving, or a roving spinning machine making yarn from sliver or a twisting machine making twist yarn from two or more yarn strands may contain a plurality of stopping devices which can utilize the process and apparatus of my invention. By yarn I mean sliver roving, simple yarn or twisted plied yarn.
The stopping devices in a spinning machine (e.g. according to U.S Pat. No. 3,636,695) are safety devices which can cause significant problems when they fail. For example as a result of yarn breakage the oncoming sliver, yarn or roving can form around the rolls of the set of drafting rolls and/or the supply rolls and these drafting rolls or supply rolls can be damaged as a result or even destroyed.
By breakdown rate or rate I mean the number of stopping devices (it is assumed that there are a number of work stations and a corresponding number of stopping devices) which are not functioning correctly at the same time, whether that is due to an internal fault or a fault in the yarn-break sensing devices associated with them which do not activate them because of any reason, i.e. they do not trigger when a yarn break occurs.